Film dosage forms that provide extended release of an active agent have been known. Such film dosage forms are known to comprise at least two layers, which include at least one mucoadhesive layer to facilitate adhesion of the dosage form to mucosa for an extended period, and a layer that acts as a diffusion barrier that prevents or restricts loss of the active agent from the dosage form to saliva in the oral cavity and ultimately to the gastrointestinal tract. The active agent can be located in the mucoadhesive layer or in a third, reservoir layer between the mucoadhesive layer and the diffusion barrier layer. Such multiple layer film dosage forms require preparation of multiple formulations, casting of multiple film layers, and combining the multiple layers into a composite, such as by casting one layer on another layer, or using a lamination process. As a result, multiple layer film dosage forms for achieving sustained release of an active agent for local delivery in the buccal cavity can be difficult and expensive to produce. Multiple-layer, sustained-release film oral dosage forms can also be annoying to some patients, as the film dosage form must be retained in the oral cavity for an extended period, all the while providing a palpable sensation that many patients find undesirable. In addition, swelling of the mucoadhesive film, may also present an important source of discomfort to the patient.
It has been suggested that mucoadhesive particles can be incorporated into oral dosage forms such as capsules, cachets, pills, tablets, lozenges, powders, granules, syrups or liquid suspensions to facilitate transport of an active agent across mucosal barriers.
It has also been suggested that mucoadhesive particles can be incorporated into ophthalmic suspensions or administered rectally, parenterally, intracisternally, intravaginally, intranasally, intraperitoneally, topically, buccally or in an oral or nasal spray.